I definitely have the same issue with Columbine, but I have enough of them in different places that I just pull out any that are somewhere I don't want them.

I also have (Midland) shooting star also. I got a half dozen and put a pair of them in different parts of the yard to see whether it would like any of them. It's doing best in a place that's shaded most of the day but gets late afternoon sun, that also stays relatively moist. Even if it does spread by seed, I'm not sure it will make it in the long term in my yard. I don't think I'm going to put the effort in to keep taller things away from it year after year.

I have been astounded at the tenacity of our (UK) native primula - by now, those crinkled rosettes of leaf are absolutely invisible beneath ramping foxgloves, hesperis and cocksfoot grass. Yet somehow manage to double in size and enthusiastically self-seed. Without any intervention from us, it is obvious that plants have developed strategies to deal with the garden bullies - early dormancy,(geranium nodosum) useful storage organs (just about all bulbs, corms and tubers), evergreen (primula vulgaris) or just sheer indestructibility (saxifrage urbium). I have been evolving (or devolving) from an anxious urban gardener to a lazy woodland owner with acreage...where doing stuff like hand-weeding (laughable) or even watering (feh!) is not going to fly one tiny bit. What has been very different has been the rate of establishment and growth. In the woods, with loads of competition and zero care, stuff either dies or limps along at glacial pace ,growing in strength and vigour at around half the rate I would expect to see on my allotment or home garden until it reaches a critical mass whereupon it storms into action. Seeds I sowed in 2012/13, are finally appearing this year (campanula trachelium, ranunculous bulbosum and thalictrum something ot other).

I finally got the courage to dig out my last Hespera plant. I was going to keep it but the numerous seedlings are a nuisance and the potential for it to become a noxious weed is too great.Will replace with natives.I'm replacing my nepeta with blue downy wild mint and my Japanese forest grass with native palm sedge.

I think plants do have survival strategies for reproducing around competition but in my small garden I have spring ephemerals growing together with wild columbine in close proximity and in the woods they have lots of room and probably would keep a safe distance from each other, plus there is more space surrounding each plant so seeds have more open area to germinate in.I grouped my plants together in a confined situation that might not be the way they would be growing in a pristine native woodland environment, and so I think I should fix the mistake by giving the ephemerals more opened space.I really love my shooting star and would love to have a small colony.I really love rainforests and am fascinated by all their plants and insects and animals and how they have evolved to need one another.I can't afford to go to the Amazon or Indonesia or equatorial Africa,but I can have a yard full of native plants and nothing but native plants and that's very much like a true rainforest.

It's true that there is more room in a natural setting but there are
also more plants. Where shooting star thrives in the wild it's
because there are limiting factors preventing other plants from
competing with it. The shooting star needs sun and moisture in the spring. I've heard that it does well in hilly situations -- limestone glades, bluffs, etc. -- especially where there is enough of a slope that other plants have a hard time getting established.

The ones that I have that do the best are at the bottom of a slight slope with the top of a stone retaining wall just below them so that there's no room for something taller to block the sun from that side. But it also helps that it's a fairly new bed and that I do a fair amount of weeding there.

I think it's likely that other plants will eventually outcompete it in my garden. I'm not sure I will go to a lot of trouble to prevent that.

My other plants were starting to outcompete the shooting star.Thats why I'm doing something about it.Besides my shooting star,I have dogtooth violets that really have suffered.They have never bloomed and they disappear and are hard to find.I moved out all the columbines.Pulled out all the jewelweed seedlings that would get big and steal sun.I had also put some non native shade plants like astilbe,pulmanaria,lady's mantle and toad lillie's in that bed.I dug out the non natives and threw them on the compost.With my Virginia bluebells the pulmanaria isn't needed.I ordered native astilbe biternata to replace the alien astilbe,but I'm planting those far away from my ephemerals.Im replacing the lady's mantle with native heuchera.I allowed enough jewelweed to grow in another bed where they won't cause trouble.Any plant that hummingbird's and bumblebees flock to stays in my yard.I moved the blue eyed grass also because they seed themselves prolifically.I moved the prenenthus.When I planted the prenanthus it was probably a first year plant and I had no idea what it was.All I knew was it seemed to stay close to the ground and the foliage was very interesting and tropical looking.When the prenanthus started to form a bloom stalk I was shocked at how tall it grew, and it was only after it flowered that I was able to identify it.Anyway I moved my prenanthus away from the ephemerals and I would recommend only moving it when the sun is going to be lost in rainclouds for a couple or few days.It's got sort of succulent like stems and doesn't like being moved.Mine is still wilted.Oh and connected to my ephemeral bed is an area where I made the huge mistake of planting Siberian squill years ago.They have spread like chives and have made their way to the fringes of my special bed.I went to start digging them out but because of the early heat wave they have already gone dormant and can't be held onto while digging to hone in on the bulb.Plus all this year's seeds will be germinating next spring.Im going to exterminate all the squill next spring but it might take 2 or 3 years before it's completely gone.If I add spring beauties and my ephemerals start multiplying they should make up for any nectar and pollen loss caused by the absence of the squill.I don't have a mound or hill to grow my shooting star on, but I've seen it grown successfully on flat ground with a little open space between it and other natives.Im keeping the toad Lilly for one more year to use as a filler.I plan on replacing them with either a clump of native Solomon's plume or false starry Solomon's seal.I just don't have enough of either to make a good sized clump this year.